Low systemic blood pressure may be routine when operating on children and often occurs with adults undergoing general anesthesia or deep sedation. Intraocular pressure levels produced by an infusion system, such as during vitreoretinal surgery, may result in occlusion of the central retinal artery if the blood pressure is low. Prolonged vascular occlusion can result in blindness. Such procedures may involve a vitreous hemorrhage, a dense cataract, or some other obstruction that may prevent a medical practitioner from being able to observe circulation in the retinal vessels. Therefore, the retinal vessels are not visible and cannot be monitored for effective blood flow.